The tiny stars you can see in the night sky are actually huge spheres of hot gas. All stars create heat and energy. The closest star to Earth is the sun. Earth and the other planets in our solar system orbit the sun. Our sun is one of billions of stars in the galaxy. It formed more than four and a half million years ago.

Fun Fact

A waterfall is an area where water drops from a high place. A waterfall usually begins with a stream or river. If the stream or river approaches a steep drop, a waterfall forms. The water moves very quickly over the edge of the drop. It is pulled to the ground by gravity. Waterfalls can be very beautiful and very powerful. The force of the falling water can be used to make electricity. This is known as hydroelectric power, and it is a renewable energy source.

Language

Correct the sentences.

1. chimpanzees is closly related to humans.

2. Chimps eat many kind of food, including plants, froot, and eggs?

[Hint: There are six errors total.]

Math

In 1900, Africa was home to nearly two million chimpanzees. Today that number has dwindled to fewer than 300,000.